U.S. 280 in Birmingham and Shelby County to get traffic signals designed to aid flow

The flow of traffic on U.S. 280 is expected to improve with the installation of adaptive traffic signals. The Birmingham News/Michelle Campbell

Birmingham, Alabama -- Drivers could be spending less time on the congested stretch of U.S. 280 between Birmingham and Shelby County once new traffic signals are installed that will monitor traffic flow and automatically change the lights' timing.

The Alabama Department of Transportation in May will begin accepting bids for adaptive traffic signals at every intersection of 280 between the Elton B. Stephens Expressway and Doug Baker Boulevard that has a traffic signal, said ALDOT spokesman Tony Harris.

The signals, the first of their kind in Alabama, will also be installed on heavily traveled stretches of East South Boulevard in Montgomery and Governors Drive in Huntsville, Harris said.

The devices will track the number of vehicles passing through each intersection at any given time, said Stacey Glass, state traffic operation engineer for ALDOT.

At times when a large number of vehicles are passing through an intersection -- such as morning and evening rush hours -- the light will stay green longer.

"This system is going to count the number of vehicles that are using that corridor and will make real-time adjustments" to ease the flow of traffic, Glass said.

Harris said they won't know how much the system will cost, or when it will be operational, until bids are in.

ALDOT officials also aren't sure exactly how much time the new system will save commuters.

"We have concluded there is some potential for improved traffic conditions," Harris said.

Successes

In Columbia County, Ga., which first began using such a system on some of its streets in 2010, the amount of time it took drivers to get from point A to point B on those roads decreased by 30 to 40 percent, said Traffic Engineer Glen Bollinger.

By the end of 2012, the system will be used at every intersection with a traffic signal in the Georgia county, Bollinger said. ALDOT officials and federal highway officials working in Alabama have examined Columbia County's system, Bollinger said.

"We had places where there were five intersections and drivers were having to stop at an average of two red lights. We've now got that down to an average of less than one stop," Bollinger said. "It works very well. You're not building more roads, but you are increasing efficiency."

In Topeka, Kan., where the first adaptive signals were installed a little more than a year ago, engineers are seeing a decrease in the amount of fuel drivers are using and a drop in carbon dioxide emissions from car exhaust, said Traffic Engineer Linda Voss. And with fewer stops, they are seeing fewer wrecks, she said.

In the first year they were used on one Topeka street used by 25,000 drivers daily, the signals reduced exhaust emissions by 191,000 pounds, saved drivers 123,000 gallons of gas, and a 28 percent decrease in crashes was reported, Voss said.

"We've been very pleased with it," Voss said.

Of course, the new signals will not alleviate all the traffic woes along 280, Harris acknowledged.

State transportation officials are still considering the possibility of building a 14-mile elevated toll highway above 280 from the Stephens Expressway to Eagle Point Parkway.

Cost estimates for the project ranged from about $1.05 billion to about $1.6 billion. Tolls collected on the highway might raise enough money to pay $300 million to $400 million of the project's total cost over 30 years, officials have said.

"It's still under consideration by the director (John Cooper). There's no decision yet," Harris said.